Thermostatically controlled firearm cooling system



Oct. 7, 1947, P. R; DE PERMENTIER 2,428,359

' THERMOSTATICALLY CONTROLLED FIREARM COOLING SYSTEM Filed Malrch 22, 1945 2 Sheets-Sheet 1 PALJLE.DEPERMENTIER,

4am www- Oct. 7, 1947. P. R. DE PERMENTIER THERMOSTATICALLY CONTROLLED FIREARM COOLING SYSTEM Filed March 22, 1945 2 She'ets-Sheet 2 3mm PAUL 1?. DE PE RMENITIEE,

a. WW2 my Patented Oct. 7, 1947 mecmosrsrr Yo m f: t' V Pine invention described he 9H may 3 We s: I

matured and used by or for the Government fog goyernmental purposes without the payment me of-any royalty thereon. t invention relates to an-iinnroyecl ethog' andapparatus for cooling machine g unstangi an mma-tic weapons in aircraft by the utilization thewair which is inevitably directed against aircna-it'in flight.

It is well known-that the life of the hanks-eithe. automatic weapons utilized on aircraf t'is EEWShOI't because of the excessive heat 639%555 during the firing thereof. Various attemptsto airtcool such barrels have been mane, themost conventional method being to proyidea perior-ated. jacket around the barrel to'pfilfpflflj' flow. oi aair therethru and therearound. method has not been successful-because thesis passages are too limited and the yelocity within the jacket is not sufiicientiy great topmovide for what may be referred. to as a ioreed cooking" of the critical parts ofthe fiting n eehaw mam, such as the barrel a nd the Joreechor-the belt, for example.

As a matter-of-fact, it is common koow eflse thatmost jacket d a rcra t, wea o d n t slaw appreciably better cooling eha-racte 'istics flight than when tested on around #159,, known that in the case oi fixed ga ns, such as wing-or fuselage guns, the barrel jaclqeteyen tends-to prevent direct sweepin of'the any cooling air. H AGcord-ingly, it is a principal obiect oi this mention to provide an improved means who; weteficie t cooling is obtain by m r e15 t flowing of the air both directly aroundthe-Joanrel and against various other parts of the n' ec lsar nismof the weapon. That is to say, acoo xiing g thisin ention, a high velocity draft of extemg air, which is induced by the-airflow; past the ai csaftziin flight, is. directed ontotheweapq sn such a way that the maximum coolinghenefits am obtained wh e y the heat-diss atin Qualities of the weapon are notably ineneasea and, consequently, its permissibie rate of {iring is favorably increased or the neg-missibissngaa tion of firing at the conventional rate is greatly increased.

As will appear, there are various ways m nten the-general principle of this invention- -may he utilized to, accomplish the objects ins mentioaee and that while they may vary in detail, they-will, as will be shown, function for thefsame put-p namely to facilitate the utilization oi aigpg'e sute against the plane which is negessarilygeo its-s9,

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li flfiifil g'irl wiiihvfihfi sl'raw ess mete is-s s a i: oierinventieo wi i'bs ma desc ib s- According tent s emha iment s own i-F a l; theresisa wing 220i anaiscnait haw-ts a m sh n gun or other automaticor weapon incorporated therein includ n Z31 ieceive l' assembiy1- 6,;with; the forward-oi ieading edgeoft-he wing z'havin giasu-itahie open: ing thereinethmwhieh theweapon may 'baiired.

Henceforth; -it---wi-l1 be unqerstood that the ma: e iinesii s tha w aves maybe e s at time and that rsszii hustisii sh s o m as. of. his? nven ion- 11 st s l o vsci. in. l th we month have a-i eitr i locket sash na and est em? or operat ng assemblysucn a 4 will 'tesssi sally con enti nal n item. t wa iois nsii r ods whereby the weapon is incorporated in an aircraft and cooled by external air.

It will also be understood that the particular wing structure of the aircraft forms no part of this invention and that, in fact, the weapon cooling means shown in. the drawing cannot only be provided for any type of aircraft in combination with any type of weapon, but the means may be incorporated either in the wing or the fuselage of .10 That is to say, theimprovement of this in n;

the plane, whichever seems more desirable.

- in the housing. An intake duct 36 is provided in .the. turret being preferably disposed in a plane ,belowthe opening thru which the nozzle or bartion comprises essentially the forcing of external air into the weapon thru ducts or nozzles etc.

which open respectively in positive and negative pressure areas external of the aircraft. In most cases, the barrel-jacket, if employed at all, will be substantially imperforate.

It will also be apparent that the barrel of the f I turret such as 40 has the barrel jacket 42 of the weapon may or may not be inclosed in a jacket member and that, furthermore, if a jacket member is used the same may or may not be perforated. In any event, the arrangement will be such that the external air thru which the aircraft naturally proceed infiight will be forcibly passed around and/or against the barrel and other critical or vital parts of theweapon by means of suitable ducts associated with the aircraft and the weapon which is an essential part thereof. 1

According to Fig. 1, there is an intake duct ID in the lower side of the wing 2 and adjacent the leading edge thereof in what may be referred to as a positive pressure area and, in any event, the intake is adapted to receive external air and to direct the same'onto the forward end portion of the barrel jacket 4. There also may be an intake duct. IZ'capable of directing incoming air, induced by the air flow past the plane in flight, into a hollow member defining what may be referred to as a chamber 5 surrounding a portion at least of the receiver assembly of the weapon. In order to achieve the maximumefiiciency and most beneficial results, it is also desirable to have an output duct such as I4 which is rearwardly of inlet I0, although it need not'necesarily be forwardly of inlet i2'as shown in the drawing.

"According to the form shown in Fig. 2, the wing 2' has a weapon the'rein provided with a barrel jacket 4' and body or receiver assembly represented generally by 6' disposed within a hollo w member 5' but'here the opening 8' thru which the gun is to be fired and the forward end of the barrel jacket have associated therewith, in any suitable manner, a cup-like member 16 mounted in the leading edge of the wing, and hence in a high pressurearea, adapted to facilitate'the reception of the cooling air and more forcibly directit upon the barrel itself. There may, or may not be, another intake duct 12' again located'in thepositive or highpressure area external of the ring, here shown as the bottom portion of the wing for'idirecting air against the receiver B'but, in any event, there will pref-'- erably be an output duct l4 substantially simil'ar'to theduct |4 previously described and directed upwardly and rearwardly into the. low pressure area above the wing.-

V In Fig.3, a wing Zf is formed to have an elongated opening ZH thru'Which barrel 4", which in this form is preferably um'acketed, projects substantially as shown. The receiver assembly 6'' is in the same relation with respect to the aircraft. and the elongated orifice orduct 20 is continuous with an output duct [4" adapted to rel jacket of the Weapon projects and this is connected to, or in communication with, an outlet duct 31 thru aflexible tube such as 38, which may consist of any conventional type of flexible hose or the like.

Fig. 5 shows still another modified form of the'turret-embodied air-cooling means wherein a flexibly-mounted weapon projecting thru a suitable opening 43 therein and a receiver assembly 44. In this form, there is a rearwardly directed output duct 46 and a flexible hose 48 communi-.

eating the same within the vicinity of the air inlet '43 and, in addition, a shield-like member 49 is associated with the forward end of the barrel jacket for inducing the reception of the cooling air thereinto so that the same is directed rearwardly thru the jacket and thence into the turret and out duct 46 by way ,of'hose 48,

Still another modification, shown in Fig. 6, discloses a barrel jacket 66 projecting forwardly from'a firearm 63 provided with a laterally-arranged intake duct62 adjacent its forward end and outtake duct 64 adjacent its rear end which is preferably directed upwardly and, of'course, rearwardly. With this arrangement, the tendency is-for the cooling air to be forced into the intake and assume a whirlwind motion around the barrel within the jacket 60.

' The forms shown in both Figs. 7 and 8 are directed to the provision of what may be stream lined covers for the air-intake ducts or nozzles. That, is to say, in some cases it maybe desirable to prevent, or at least substantially reduce, the forcing of air into the wing or fuselage when firing is not being done andwhen, therefore, cooling is not necessary. a

To this end, there is shown a wing 70 having a forward opening or chamber 12 through which the barrel jacket 14 extends and the receiver as sembly 16 of the weapon is disposed within the wing. Cover member 18, preferably of the socalled clam-shell typ is associated with the forward side of the aircraft and the weapon adjacent the opening thru which the latter is to fire, and while the operation of this member may be controlled in various ways, there is shown a spring for'normally holding thecooper'ating jaws of the cover member in closed position, as when the gun does not require cooling, but to permit moving thereof to open position when air is desired to be forced into chamber 12 and ontofthe barrel, and thence out suitable outlet 82. The opening and closing of this cover member is preferably controlled from within the aircraft, as from the pilot's seat, and this maybe obviously accomplished in several ways. That is to say, there may be a thermostatic device or solenoid 'ac'tuatedmeans whereby the cover may be kept open as long'as the weapon requires cooling or the pilot" or any other member of the crew may energiz'e 'the operating mechanism to close or open'the"cove'r"" as desired. In the drawings (Figs. 7 and 8), there are shown control wires 84 actuated by solenoid 86 Which may be energized by battery 81 either from the pilots seat, for example, as by a switch 88, or from a thermostat 90 controlled by the temperature of the barrel and its need for cooling. Preparatory to firing, the gunner closes the switch 88 to thereby energize the solenoid 86 and cause the separation of the cover members 18. Upon firing heat emitted at the gun breech effects the thermostat 90 to continue the energization of the solenoid 86 and hence continue the separation of the cover members 18 after the gunner has released the switch 88.

It will be noted that in all cases the arrangement is such that the weapon may forcibly receive air as the plane is in flight. The air intake duct in each disclosed form of the device designated by the numerals I0, I2, I2, l6, 2|], 36, 49, 62 and 12, consists of some form of tubular member, having an outwardly flared end or not, but in any case eventually leading directly against the barrel and preferably adjacent its forward end. At the same time, there is an output having its inner end disposed within the wing or fuselage, whichever the case may be, and its outer end facing in the opposite direction so as to permit the escape of the air and facilitate the velocity of the air flow.

It will be appreciated that the construction of this invention is such that there is created a possible contact of cooling air with critical parts of the weapon at a relatively high velocity and particularly against such parts of the weapon mechanism which would ordinarily be without the stream of air which naturally is forced against the front of the plane when in flight.

With the arrangements heretofore described, it will be noticed that the positive air pressure is taken in from the high pressure area of the wing or fuselage surface and immediately distributed and allowed to become discharged into the low, or what may be referred to as the negative, pressure area, with the result that there is in effect a combined compression and suction force which provides a distributed velocity of flow without producing any objectionable drag.

I claim:

1. In combination, an aircraft wing, an automatic firearm disposed therein to fire forwardly from the leading edge of said wing, a housing about the forward part of said automatic firearm, said housing being in communication as to its interior with the leading edge of said wing, an air outlet of generally tubular cross section extending from the rear end of said housing into the slipstream of the wing being turned backward in said slipstream and being in interior communication with said housing, a cover member of the clamshell type mounted on the forward end of said housing, solenoid means mounted within the aircraft for opening said cover to form an air scoop, thermostatic means responsive to the temperature of the barrel part of said firearm for continuously maintaining the opening of said cover during the emission of heat by said firearm barrel, and spring means on said cover for closing the latter when said solenoid cover opening means is deenergized.

2. A firearm cooling device for installation in a support, comprising in combination a firearm emitting heat during its operation, a duct chamber, axially of which said firearm is disposed and having an air intact port at one end and an air discharge port at the opposite end thereof, a cover member at the air intake end of said duct chamber for releasably restricting the admission of air thereinto, manually operable means for opening said cover member, and means for maintaining said cover member open during the operation of said firearm and thermostatically controlled by heat emitted from said firearm.

PAUL R. DE PERMENTIER.

REFERENCES CITED The following references are of record in, the file of this patent:

UNITED STATES PATENTS Number Name Date 2,221,905 Berlin Nov. 19, 1940 2,273,839 De Port et al Feb. 24, 1942 FOREIGN PATENTS Number Country Date 413,968 Great Britain July 26, 1934 457,570 Great Britain Dec. 1, 1936 510,709 Great Britain Aug, 4, 1939 804,838 France Aug. 10, 1936 

